Grinding wheel dressing device



M y 5, 1953 D. ALDERMAN 2,637,312

GRINDING WHEEL DRESSING DEVICE Filed Dec. 17, 1951 3 Sheets-Sheet l INVENTOR. DALE AL DERM/I/V m WM ATTORNEY y 5, 1953 D. ALDERMAN 2,637,312

GRINDING WHEEL DRESSING DEVICE Filed Dec. 17, 1951 3 Sheets-Sheet 2 INVENTOR. DALE ALDERMA/v May 5, 1953 D. ALDERMAN 2,637,312

GRINDING WHEEL DRESSING DEVICE Filed Dec. 17, 1951 5 Sheets-Sheet 3 EN TOR. ERMA /V INV DALE ALD ATTORNEY Patented May 5, 1953 UNITED STATEd ih'lhN'l GFFlC'E GRINDINGWHEEL DRESSKNG nnvios Dale -,Alder1nan, Birmingham, Mich.

Application December 17, 1951, Se'rialNo. 262,080

(or. 125ll) 10 Claims. 1

This invention relates to devices for dressing grinding wheels and particularly to the type of Wheel dresser which is disclosed in Patent 1,912,410 issued. to Shotey.

In that patent, a device is disclosed, which is intended to form concave .involute surfaces on a grinding wheel, in order that such surfaces may be used to form corresponding convex involute surfaces on the teeth of gears and the like.

The "Shotey patent employed the previously known principle of generating a common involute curve by moving a tangent member about the periphery of an alienate-member. That patent reduced to its simplest factors disclosed a particular means for clamping the tangent memher 'to the 'arcuate member to obviate slippage, by employing an arm pivoted at the center of the arcuate member.

I have found that the structure disclosed by Shotey has certain inherent shortcomings, and that it is impractica is for use in generating involute curves having comparatively small radii. For example, it is impossible to use the Shotey device on grinding Wheels used to grind delicate gages, where the arcuate member employed might have a diameter as small as one-eighth of an inch. In such applications, the Shotey structure cannot be held against slippage, and

because in the Shotey structure, the pressure is applied to the tangent member from one side only of the arcuate member, there is a tendency to deflect the central shaft of the arcuate member, which affects the accuracy and smooth operation of the dresser. In arcuate members of small radius, the results of such deflection are out of proportion to the percentage of tolerance allowed, and by the same token the deflection invariably causes the shearing off of the tiny pivot at the center of the arcuate member.

It is therefore an object of this invention to obviate the foregoing difficulties and to provide a greatly improved device for dressing grinding wheels.

Another object of the invention is to provide a tangent bar clamping structure, which develops balanced pressures on the arcuate member or base circle element.

A further object of the invention is to provide positive anti-slippage and linkage mechanism elements in the nature of a rack and gear between the periphery of the arcuate member or base circle and the tangent bar.

A still further object of the invention is to provide a device of the character indicated, which is provided with a carrier rod which practically floats about the arcuate member or the base circle.

Another object of the invention is to provide a structure of the character indicated, which is constructed and arranged with resilient adjustment between the arcuate member and the floating rod and tangent bar.

Another object of the invention is to provide a device of the character indicated, which is constructed and arranged with means to make a three point contact on the base circle-or 'arcuate member.

A further object of the invention is to pro vide a device of the character indicated, in which the working point of the dressing tool is posi-' tioned below the plane of tangency of the tangent or beam, whereby a prolate involute curve is developed instead of a common involute curve as disclosed by Shotey.

The foregoing, and other objects and advantages of the invention will become more apparent as the description proceeds, reference being made from time to time to the accompanying drawings, forming part of the Within disclosure, in which drawings:

Fig. l is a perspective view of a device embodying the invention.

Fig. 2 is a side elevational view of the device shown in Fig. 1.

Fig. 3 is a fragmentary plan view of the under face of the rocker shown in Fig. i, and is taken substantially on the line 33 of Fig. 4.

Fig. 4. is a perspective view of a modified form of the invention.

Referring now more particularly to the drawings, it W11 be understood that the reference characters l and 8 indicate a pair of base members to which are secured, by any suitabl means, the uprights 9, Ill, H, and 12, which serve as stabilizers and guides for the rolling beam or tangent bar hereinafter described. Anchor blocks l3 and M are respectively secured to the front faces of the upright members Id and I2 by any suitable means. I provide the anchor blocks is and it because they may be machined or ground with great accuracy, which is all important in the assembling of this device, in order that the work done thereon may be held to very close tolerances. Secured to the front of the anchor blocks is and M, by welding or other suitable means as at E5, is a tie bar it, which serves to join the pairs of uprights 9, H), H, and it. The tie bar It also serves as a support for the base shoe I! to which it is secured by welding or other suitable means. The base shoe ll serves as a support for the device when it is desired to slidably mount the device on a rail (not shown), so that the device may be slid forwardly or backwardly, in which event the lower ends of the guide members 9, Ill, II, and I2 serve to hold the device in proper alignment on the rail (not shown).

The base shoe I! has an upwardly directed member l3, which serves as a support for the base circle or arcuate member IS. The base circle l9 has the proper curvature to develop the desired involute curve to be imparted to the wheel, which is to be dressed. The arcuate member H! has off-sets 20, which serve as stops for the lower end of the carrier rod hereinafter described. It wil be understood that the arcuate member if) is secured against rotation to the supporting member [8 by means of machine screws 2| or any other suitable means. It will also be understood that arcuate members of different size may be used, replacing one with another. A reinforcing block 22 is preferably used to give added rigidity to the upright member l8.

Resting on the upper periphery of the arcuate member it is a tangent beam 23 which is adapted to roll thereon. The beam 23 is preferably made of very hard tool steel and has machined, or otherwise formed, on its lower face a plurality of accurately cut teeth 24, which are adapted to engage corresponding teeth 25 formed on the periphery of the arcuate member l9. These teeth, although of comparatively small dimensions are accurately formed with extremely close tolerances, and mesh with one another to effect a rack and gear function, which is an important feature of this invention and enables me to hold the working parts of this dresser to extremely close tolerances.

In the Shotey patent, hereinabove referred to, he discloses that the surfaces between the tangent bar and the periphery of the arcuate member might be roughened to prevent the slippage between parts. There could be no inter-engaging or accurate meshing of the elements of the several parts when so roughened as indicated by Shotey, but rather there might be a contacting of the high points of the roughened elements, during one passage of the tangent bar over the periphery of the arcuate member, and possibly during the next passage, the high points of one element might contact certain of the low points of the roughened area of the other element, all of which would cause more slippage and greater inaccuracy in the operation of the Shotey device. Such inaccuracies would be intolerable in the making of extremely fine gages, where the over-all diameter of the respective arcuate members or base circles employed might be as small as one-eighth of an inch.

The tangent bar 23 is adapted to travel between the up-right members 9, H], H, and [2. One face of the tangent bar 23 is adapted to closely engage the inner faces of the guide members l and I2, against which it is resiliently urged by means of spring b acked detents 26, which are adapted also to engage the inner faces of the up-right guide members 9 and H. A handle 21 is provided to roll the tangent bar 23 about the periphery of the arcuate member [9.

A tool holder 28 is secured, as at 29, to accurately machined extension members 30, formed as integral parts of the tangent bar 23. A conventional wheel dressing tool 3| is supported in a V groove, formed in the end of the tool holder 28, and is secured in position by means of a locking plate 33, which is held in position by machine screws 34 or other suitable means. An

adjusting screw 35 is provided for the tool so that the tool may be held in proper adjustment. It will be understood that the working point of the tool 3| is positioned below the plane of tangency of the bar 23, so that a prolate involute instead of a common involute curve is developed on the wheel.

In order to hold the tangent bar 23 in close peripheral contact with the arcuate member I9, I provide a carrier rod 36 which floats about the arcuate member I9, as hereinafter described. Threaded to the lower end of the carrier rod 36 is a roller support 3'1, in which is mounted for rotation a, pair of rollers 38, which are adapted to roll along the lower portion 39 of the arcuate member 19. The stops [9 and 20 serve to limit the movement of the roller carrier 31. Slidably mounted near the upper end of the carrier 36 is a second roller carrier 40, in which is mounted for rotation a pair of rollers 4|, which are adapted to ride on the upper surface of the tangent bar 23. A pressure nut 42 and lock nut 43 are provided so that I may exert the desired pressure between the rollers 38 and the arcuate member 19, and between the rollers 4| and the tangent bar 23. I have also provided a compression spring 44, so that the pressure exerted by the nuts 42 and 43 may be resiliently controlled. It will be seen that with this structure I am enabled to provide balanced pressures at the opposite sides of the arcuate member I9. This obviates any tendency of the tangent beam 23 to be deflected sideways, and further prevents the shearing off of the small pivot required to support an arcuate member of relatively small diameter. This floating carrier rod structure also enables me to make quick changes of parts and obviates all of the difficulties inherent in securing the carrier arm 36 to the center of the arcuate member as disclosed by Shotey.

In Fig. 4, I illustrate a stream-lined version of a device embodying the invention. In this version of the invention, I provide a unitary base member 47, which has downwardly directed flanges 48, which serve as guides when the device is mounted on a rail or the like. A cut out 49 is provided to accommodate a bolt or machine screw for securing the device in position on a lathe or other machine. Centrally positioned in the upper part of the base member 41 is a bifurcated member 50, which has its upper edges 5| curved. The bifurcated member 58 is adapted to support and hold against rotation the arcuate member 52, the outer periphery of which is provided with accurately formed teeth, as hereinabove described, which teeth are adapted to mesh with corresponding teeth 53 (Fig. 3) formed in the under face of the rocker 54. The rocker 54 corresponds to the beam 23 as shown in Figs. 1 and 2. The rocker 54 is in substance a rectangular plate member having downwardly extending flanges 55 and 56 and a downwardly extending curved member 51, which extends into the opening 58 formed in the bifurcated member 50. The side walls of the opening 58 serve as guides for the element 51 formed on the rocker 54. A mounting plate 59 is secured to one side of the rocker 54 and has attached to it, as at 60, by means of machine screws 61 or other suitable means, the tool holder 62, to which is secured a dressing tool 63, which is held in position by means of a U shaped member 64 and set screw 65. The rocker 54 is manipulated with a conventional handle 66, so that the dressing tool 63 may be brought into and moved out of engagement with the grinding wheel 61, which is to be dressed. A carrier rod 63, similar to the one previously described, is provided at either end with roller carriers 69 and Ill. The roller carrier 69 has mounted on it for rotation two rollers ii and 12, which are adapted to roll on the periphery of the basecircle member or arcuate member 52, and the carrier member has mounted on it for rotation rollers 13, which are adapted to roll along the top surface of the rocker 5%. A pressure nut it engages threads on the carrier rod 38, so that balanced pressures may be exerted on the roller carriers 69 and 70, which in turn exert equal pressures on the rollers 1| and 12 and the roller '13, which pressures are in turn imparted to the base circle or arcuate member 52 and the top of the rocker 54. Although the base circle or arcuate member 52 in Fig. 4 is shown comparatively large, it will be understood that it may assume a size as small as one-eighth of an inch in diameter. The device as illustrated in Fig. 4 functions in exactly the same manner as the device shown in Figs. 1 and 2. That is, when the member 54 is rocked about the periphery of the member 52, a prolate involute curve is developed at the point of the dressing tool 63, which involute in turn is transferred to the dressing wheel 61.

It will be understood that the device may be used with equal facility for dressing grinding wheels used for internal grinding as well as external grinding.

Having described my invention, what I claim and desire to secure by Letters Patent is:

1. In a device of the character described, in

combination a base, an arcuate member supported against rotation by said base, a tool supporting straight tangent member in non-slipping rocking contact with the periphery of said arcuate member, a carrier rod positioned adjacent to and across one face of said arcuate member and extending beyond the axis of said arcuate member, said carrier rod being secured to a carrier at either end thereof, a pair of spaced rollers supported for rotation in each of said carriers, the rollers of one carrier being in rolling contact with the outer periphery of said arcuate member, the rollers of the other carrier being in rolling contact with the outer surface of said tangent member.

2. The structure of claim 1, in which the periphery of said arcuate member and the periphery contacting face of said tangent bar are provided with accurately formed, co-acting and meshing teeth.

3. The structure of claim 1, including a tool the working point of the tool being supported by the tangent bar in a plane removed from the plane of tangency of said bar.

4. The structure of claim 1, in which one end of said rod is threaded, there being a nut on said threads, and a spring between said nut and the adjacent carrier, whereby to urge said carrier toward the other.

5. A device for dressing grinding wheels comprising a base, an arcuate member secured to said base and having off-sets thereon arranged to serve as stops, a member rockable on the periphery of said arcuate member, inter-engaging teeth on said arcuate member and said rockable member, a carrier rod, a carrier secured to each end of said rod, rollers on each of said carriers,

the rollers of one carrier being in rolling contact with a portion of the periphery of said arcuate member, the rollers of the other carrier being in rolling contact with an outside surface of said rockable member, and threads on one end of said carrier rod and a nut on said threads whereby to move one of said carriers toward the other on said rod.

7. The structure of claim 5, in which the travel of one of said carriers is limited by the stops on said arcuate member.

8. In a device of the character described, in combination a base, an arcuate member supported thereby, a tool holding tangent member in rocking contact with said arcuate member, upright members secured to said base and serving as guides and stabilizers for said tangent member, inter-meshing teeth on said tangent member and said arcuate member, a carrier rod supported alongside said arcuate member, said rod having rollers secured thereto, certain of said rollers be ing arranged to contact said arcuate member and certain of said rollers being arranged to contact one face of said tangent member.

9. The structure of claim 8, in which said tangent member is provided with spring backed detents arranged to slidably contact at least one of said uprights.

10. The structure of claim 8, including a hand grip whereby said tangent member may be rocked on said arcuate member.

DALE ALDERMAN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,912,410 Shotey June 6, 1933 2,237,975 Wainright Apr. 8, 1941 2,337,144 Young Dec. 21, 1943 

